Dissolved organic carbon is released from sealings and glues of pore-water samplers

To quantify solute concentrations in soil pore waters, their alteration on contact with sampler components should be negligible compared with naturally occurring concentrations. We hypothezise that elastomer sealings and glues are potential sources of dissolved organic C (DOC) in pore water samples. We immersed different sealing materials and filled assembled samplers with water and determined the release of DOC from glues, elastomers, and other components of suction cups and plates into water samples. Between 0.8 and 63 mg DOC L-1 were released on contact with sampler parts. We conclude that soil solution samplers should be designed without glues or elastomers, if DOC concentrations <10 mg L-1 are the targets of investigations and expected flux rates are low. Glass suction plates entirely made from borosilicate glass avoided the contamination of samples with sealing derived DOC.